CN114300256B

CN114300256B - Manufacturing method of high-voltage winding

Info

Publication number: CN114300256B
Application number: CN202111647970.7A
Authority: CN
Inventors: 马婷婷; 张鑫鑫; 刘亚飞; 张小容; 刘超; 马斌
Original assignee: Jiangsu Shemar Electric Co Ltd
Current assignee: Jiangsu Shemar Electric Co Ltd
Priority date: 2021-12-29
Filing date: 2021-12-29
Publication date: 2024-06-14
Anticipated expiration: 2041-12-29
Also published as: CN114300256A

Abstract

The application discloses a manufacturing method of a high-voltage winding, which comprises the following steps: step a: arranging and fixing the winding part on the preparation mold along the circumferential direction of the preparation mold; step b: winding a high-voltage coil with a tap switch on a winding part by a guide wire; step c: the winding part wound with the high-voltage coil is taken as a body to be injected and is placed into an injection machine together with a preparation mould, and high-temperature vulcanized silicone rubber is integrally injected at the periphery of the body to be injected to form a high-voltage insulating layer, so that a high-voltage winding is obtained; step d: the high voltage winding is released from the preparation mold. The manufacturing method of the high-voltage winding has simple steps, the required manufacturing mould has simple structure and is easy to manufacture, and the high-voltage winding manufactured by the method omits the structure of the rigid insulating lining barrel, so that the high-voltage winding has better heat conduction effect, and no interface between the high-voltage insulating layer and the rigid insulating lining barrel exists, thereby the situation of surface discharge of the rigid insulating lining barrel does not exist, the materials are saved, and the cost is reduced.

Description

Manufacturing method of high-voltage winding

Technical Field

The application relates to the technical field of power transformers, in particular to a manufacturing method of a high-voltage winding.

Background

The traditional dry-type transformer high-voltage winding skeleton consists of a rigid insulating lining cylinder, a rigid insulating winding groove and a cake-type winding (or called a wire cake) with insulating film wires, and the skeleton is covered by a high-voltage insulating layer to form the high-voltage winding. The rigid insulating lining cylinder is an inner supporting body wound by a wire and plays a supporting role, but the heat conduction effect of the rigid insulating lining cylinder is poor, an interface formed on the outer surface of the rigid insulating lining cylinder weakens the insulating strength of a high-voltage insulating layer, the surface discharge of the rigid insulating lining cylinder is extremely easy to cause under the effect of lightning transient high voltage, and the use of the rigid insulating lining cylinder increases the size of a product in the radial direction, so that copper-iron materials are increased, and the cost is high.

Disclosure of Invention

Aiming at the defects of the prior art, the application aims to provide a manufacturing method of a high-voltage winding, which has simple steps, a required manufacturing mould is simple in structure and easy to manufacture, and the high-voltage winding manufactured by the method omits the structure of a rigid insulating lining cylinder, so that the high-voltage winding has better heat conduction effect, and no interface between a high-voltage insulating layer and the rigid insulating lining cylinder, thereby avoiding the surface discharge of the rigid insulating lining cylinder, saving materials and reducing cost.

In order to achieve the above purpose, the technical scheme adopted by the application is as follows: the method for manufacturing the high-voltage winding comprises a winding part, a high-voltage coil and a high-voltage insulating layer, wherein a wire is wound on the winding part to form the high-voltage coil, and the high-voltage insulating layer wraps the high-voltage coil and the winding part, and the method comprises the following steps of:

Step a: arranging and fixing the winding part on the preparation mold along the circumferential direction of the preparation mold;

Step b: winding a high-voltage coil with a tap switch on a winding part by a guide wire;

step c: the winding part wound with the high-voltage coil is taken as a body to be injected and is placed into an injection machine together with a preparation mould, and high-temperature vulcanized silicone rubber is integrally injected at the periphery of the body to be injected to form a high-voltage insulating layer, so that a high-voltage winding is obtained;

step d: the high voltage winding is released from the preparation mold.

Preferably, the preparation mould includes barrel and two end covers that are located the barrel both ends, sets up a plurality of joint holes along the circumference of end cover, and two end covers are symmetrical structure each other, and the both ends of wire winding portion set up a plurality of arches, in step a, correspond the matching with a plurality of joint holes with a plurality of arches and fix wire winding portion on the preparation mould through the end cover. The winding part is fixedly connected to the preparation mould through the bulge, an adhesive is not needed to bond the winding part to the preparation mould, the cost can be saved, the assembly time can be saved, and the production efficiency can be improved.

Preferably, before the step a, at least one end cover and the cylinder are fixed in advance, so that the step of assembling one end cover and the cylinder can be omitted, and the production efficiency is improved.

Preferably, at most one end cap is integrally formed with the barrel or secured by welding.

Preferably, step a comprises:

Step a1: one end of the winding part is fixed on one end cover of one end of the cylinder;

Step a2: the other end cover at the other end of the cylinder body is fixedly connected with the cylinder body after being clamped with the other end of the winding part.

Preferably, the wires include a first wire and a second wire, and in the step b, the first wire is wound from the first end of the winding part to the middle of the winding part along the axial direction of the high-voltage winding, and is led out of the first tap changer; the second wire is wound from the middle of the winding part to the second end of the winding part along the axial direction of the high-voltage winding, and is led out of the second shunt switch.

Preferably, in step d, at least one end cap is removed, separating the high voltage winding from the preparation mould.

Preferably, step d is followed by step e: cutting the bulge and polishing the bulge smoothly to prevent partial discharge.

Preferably, the clamping hole is a rectangular hole, and the protrusion is a rectangular protrusion. The design of rectangle arch and rectangular hole compares in cylinder arch and circular hole, and stability is stronger, and the wire winding portion can not take place the rotation round circular hole, and then avoids leading to the deflection of wire winding portion.

The beneficial effects of the application are as follows: the manufacturing method of the high-voltage winding has simple steps, the required manufacturing mould has simple structure and is easy to manufacture, and the high-voltage winding manufactured by the method omits the rigid insulating lining barrel, so that the high-voltage winding has better heat conduction effect, and no interface between the high-voltage insulating layer and the rigid insulating lining barrel exists, thereby avoiding the surface discharge of the rigid insulating lining barrel, saving materials and reducing cost.

Drawings

Fig. 1 is a front view of a dry-type transformer 10 according to an embodiment of the present application;

fig. 2 is a top view of a dry-type transformer 10 according to an embodiment of the present application;

fig. 3 is a front view of an assembled core 110 according to an embodiment of the present application;

fig. 4 is an enlarged view at G in fig. 2;

fig. 5 is a front view of a core clip 140 according to an embodiment of the present application;

Fig. 6 is a side view of a core clip 140 according to an embodiment of the present application;

fig. 7 is a schematic perspective view of a high voltage winding 130 according to an embodiment of the present application;

Fig. 8 is a perspective view of a high voltage coil 1320 wound around a winding portion 1310 according to an embodiment of the present application;

FIG. 9 is a simplified electrical schematic diagram of a high voltage coil 1320 in accordance with an embodiment of the present application;

fig. 10 is a schematic perspective view of a manufacturing mold 20 according to an embodiment of the present application;

fig. 11 is a schematic diagram showing connection between the winding portion 1310 and the manufacturing mold 20 according to an embodiment of the present application.

Detailed Description

As required, specific embodiments of the present application will be disclosed herein. However, it is to be understood that the embodiments disclosed herein are merely exemplary of the application, which may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present application in virtually any appropriately manner, including employing the various features disclosed herein in connection with features that may not be explicitly disclosed.

The term "coupled" as used herein is to be interpreted broadly, unless explicitly stated or limited otherwise, as the term "coupled" as used herein, as defined in the context of the present application, as defined in the claims, and as the term "coupled" as used herein, as defined in the claims. In the description of the present application, it should be understood that the directions or positional relationships indicated by "upper", "lower", "end", "one end", etc., are based on the directions or positional relationships shown in the drawings, are merely for convenience of description and simplification of the description, and do not indicate or imply that the apparatus or element in question must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as limiting the application.

As shown in fig. 1-3, the dry-type transformer 10 is a three-phase transformer, a-phase, B-phase and C-phase, respectively, i.e., the dry-type transformer 10 includes three single-phase transformers 100. The three transformers 100 may be arranged to form a linear or triangular structure according to the structure of the core 110, and the three transformers 100 are symmetrically constructed. The dry-type transformer 10 may be an isolation transformer, a variable frequency transformer, a test transformer, or the like.

In one embodiment, with continued reference to fig. 1-3, three transformers 100 are arranged in a linear configuration, and dry-type transformer 10 includes a core 110, three low voltage windings 120, and three high voltage windings 130. The iron core 110, the low voltage winding 120, and the high voltage winding 130 are sequentially arranged from inside to outside. The iron core 110 includes three columnar iron core bodies 111, an upper yoke 112 located at the upper ends of the three columnar iron core bodies 111, and a lower yoke 113 located at the lower ends of the three columnar iron core bodies 111, the three low-voltage windings 120 are respectively sleeved on the peripheries of the three columnar iron core bodies 111, the three high-voltage windings 130 are respectively sleeved on the peripheries of the three low-voltage windings 120, namely, the three columnar iron core bodies 111, the three low-voltage windings 120 and the three high-voltage windings 130 are sequentially sleeved one by one from inside to outside. The columnar iron core body 111 is formed by stacking a plurality of layers of silicon steel sheets, binding and fixing are performed on the plurality of layers of silicon steel sheets by using binding tapes, and the radial section of the columnar iron core body 111 is approximately elliptical or circular or other shapes, so long as the columnar iron core body can be accommodated in the hollow cavity of the low-voltage winding 120, and the columnar iron core body is not limited herein. The upper yoke 112 and the lower yoke 113 are also formed by stacking a plurality of silicon steel sheets, and the three columnar iron cores 111 are fixedly connected to form the iron core 110.

Illustratively, the present application provides a simple method of assembling the core 110, the low voltage winding 120, and the high voltage winding 130. The lower yoke 113 of the iron core 110 is formed by stacking multiple layers of silicon steel sheets and is arranged at the bottom of the dry-type transformer 10, then multiple layers of silicon steel sheets are respectively inserted into two ends and the middle part of the lower yoke 113 to form three columnar iron core bodies 111, then a low-voltage winding 120 and a high-voltage winding 130 are sequentially sleeved outside the columnar iron core bodies 111, finally multiple layers of silicon steel sheets are horizontally inserted into the upper ends of the three columnar iron core bodies 111 to form an upper yoke 112, and accordingly the assembly of the iron core 110, the low-voltage winding 120 and the high-voltage winding 130 is completed.

Referring to fig. 1-2 and fig. 5-6, a core clamping member 140 is disposed on an outer side of the core 110, and the core clamping member 140 is used for clamping the core 110. The iron core clamping piece 140 is formed by connecting three clamping pieces, wherein the three clamping pieces are plates, the clamping piece positioned at the middle position is defined as a first clamping piece 142, the other two clamping pieces are defined as second clamping pieces 143, and the two second clamping pieces 143 extend in the same direction on two sides of the connection of the first clamping piece 142 and the two second clamping pieces 143, so that the iron core clamping piece 140 is in a channel steel-like structure, and a 匚 -shaped structure can be formed. Preferably, the second clamping member 143 is disposed perpendicular to the first clamping member 142. The first clamping member 142 is configured to be abutted against the core 110, and the second clamping member 143 is configured to face away from the core 110. After the iron core clamping member 140 is installed, the plate surface of the first clamping member 142 is disposed along the axial direction of the iron core 110, and the plate surface of the second clamping member 143 is disposed along the radial direction of the iron core 110. Specifically, in an application scenario, the axial direction of the iron core 110 is along the vertical direction, and the radial direction of the iron core 110 is along the horizontal direction. Of course, in other embodiments, the core clamping member may be a rectangular hollow pipe, that is, the core clamping member is formed by mutually connecting and surrounding four clamping members with plate structures to form a closed structure, and the structure of the core clamping member is more stable; or the core clamps are interconnected by five, six or more plate structured clamps and are enclosed to form a closed structure, without limitation.

The number of the iron core clamping pieces 140 is four, wherein two iron core clamping pieces 140 are symmetrically positioned at two sides of the upper end of the iron core 110, and the upper end (namely the upper iron yoke 112) of the iron core 110 is clamped and then fixedly connected through a first fastener; the other two core clamping members 140 are symmetrically located at two sides of the lower end of the core 110, and are fixedly connected by a second fastening member after clamping the lower end of the core 110 (i.e., the lower yoke 113). The first fastener and the second fastener each use a plurality of screws and bolts that are matched with each other to clamp two ends of the iron core 110 through the two iron core clamping pieces 140. The core clamping member 140 has first through holes 141 formed at both ends thereof, and specifically, two first through holes 141 are formed at both ends of the first clamping member 142. Two core clamping pieces 140 are correspondingly placed at two sides of the upper end of the core 110, screws (not shown) are simultaneously inserted into two first through holes 141 at the same end of the two core clamping pieces 140, and then are screwed and fixed by bolts, so that two ends of the two core clamping pieces 140 are fixed, and the two core clamping pieces 140 clamp the upper end of the core 110. The two core clamping members 140 at the lower end of the core 110 also fix and clamp the lower end of the core 110 in the same manner, which is not described in detail. In addition, to further reliably clamp the core 110, the middle portion of the core clamping member 140 also employs a plurality of screws and bolts that are used in cooperation with each other to clamp the middle portion of the core 110. The second clamping member 143 is further provided with a second through hole (not shown) for connection with the low voltage winding 120.

The core clamping member 140 is made of a fiber reinforced composite material, specifically, may be formed by compression molding with glass fiber impregnated epoxy resin, or may be formed by compression molding with aramid fiber impregnated epoxy resin, or may be made of other composite materials, where the first clamping member 142 and the second clamping member 143 are integrally formed, which is not limited herein.

The fiber reinforced composite material refers to a composite material formed by winding, die pressing or pultrusion of a reinforcing fiber material, such as glass fiber, aramid fiber and the like, and a matrix material.

In other embodiments, the core clamping member may be made of a metal material, for example, the first clamping member and the second clamping member may be different sidewalls of an integrally formed channel steel, or may be integrally formed and then connected and fixed by welding. At this time, an insulating member such as a small post insulator is required to be attached to the outside of the core clip to insulate the high and low voltage wire from the metal channel. Meanwhile, an insulating pad is arranged outside the iron core, so that the iron core and the iron core clamping piece are insulated, and electromagnetic loss of the iron core caused by eddy current generated on the iron core clamping piece is avoided.

In this embodiment, compared with the core clamping piece of the traditional channel steel structure, the core clamping piece 140 made of the fiber reinforced composite material has more excellent economic performance, the insulating pad fixed on the outer surface of the core 110 can be omitted, the cost of the fiber reinforced composite material is lower, and the overall cost can be reduced by about 60%. Meanwhile, because the traditional channel steel structure is made of metal conductive materials, additional insulating components such as small post insulators are required to be connected to the iron core clamping pieces for insulation, so that on one hand, the cost is increased, on the other hand, the weight of the whole equipment is increased, the noise is large in the running process of the equipment, the carbon emission is large in the production process of iron products, the pollution is serious, and the iron core clamping pieces 140 made of fiber reinforced composite materials solve the problems; in addition, the core clip 140 made of the fiber reinforced composite material does not generate eddy current loss in the composite body, thereby reducing the no-load loss of the dry-type transformer 10. In summary, the iron core clamping piece 140 made of the fiber reinforced composite material has low cost, light weight and good mechanical property, and the carbon emission in the production process of the fiber reinforced composite material is low, and the iron core clamping piece is more green and environment-friendly.

As shown in fig. 2 and 4, the low voltage winding 120 includes a copper foil 121, a low voltage insulation layer 122, and a support bar 123, and the copper foil 121 and the low voltage insulation layer 122 are alternately arranged. The copper foil 121 is formed by winding a whole piece of copper foil paper, and the low-voltage insulating layer 122 and the copper foil 121 are overlapped and then wound together, so that the alternating arrangement of the copper foil 121 and the low-voltage insulating layer 122 is realized. At least one heat dissipation air passage is arranged in the low-voltage winding 120, and the heat dissipation air passage is positioned between the adjacent copper foil 121 and the low-voltage insulating layer 122, and a supporting bar 123 is positioned in the heat dissipation air passage and used for supporting and isolating the adjacent copper foil 121 and the low-voltage insulating layer 122. Specifically, the supporting strips 123 are insulating supporting strips 123, when the copper foil 121 and the low-voltage insulating layer 122 are overlapped and wound to a fixed thickness, the insulating supporting strips 123 are fixed on the outer surface of the low-voltage insulating layer 122 or the copper foil 121, and the overlapped and wound are continued so that the copper foil 121 or the low-voltage insulating layer 122 is closely attached to the insulating supporting strips 123, and the insulating supporting strips 123 can be fixed between the adjacent copper foil 121 and the low-voltage insulating layer 122 in an adhesive manner, or can be fixed by a pressing force generated during winding or other manners. A plurality of insulating support bars 123 are arranged in each layer of heat dissipation air passage, and the plurality of insulating support bars 123 are arranged at intervals along the circumferential direction of the outer circumferential surface of the copper foil 121 and play a role in supporting the adjacent copper foil 121 and the low-voltage insulating layer 122. At least two, three, four or more insulating support bars 123 are provided in each layer of heat dissipation air passages. Preferably, a plurality of insulating support bars 123 of the same layer are uniformly spaced along the circumferential direction of the outer circumferential surface of the copper foil 121. The copper foil 121 and the low voltage insulation layer 122 are continuously overlapped and wound to a predetermined thickness after the insulation support bar 123 is disposed to form the low voltage winding 120. The arrangement of the heat dissipation air passage can release heat generated by the low-voltage winding 120 in the operation process of the dry-type transformer 10, so as to avoid overheat failure of the dry-type transformer 10. The heat dissipation air passage may be provided with one layer, or may be provided with two or more layers, which is not limited herein.

The low-voltage insulating layer 122 is made of polyimide impregnated paper, specifically, SHS-P diphenyl ether prepreg, and is formed by baking after impregnating diphenyl ether resin with polyimide film and polysulfone fiber non-woven soft composite material, and of course, the low-voltage insulating layer can also be made of DMD insulating paper or silicone rubber film, or other insulating materials, and is selected according to different temperature rise grades of the dry-type transformer.

The insulating support bar 123 is made of glass fiber-impregnated epoxy resin or aramid fiber-impregnated epoxy resin, which is not limited herein. The insulating support bar 123 is a long bar with an i-shaped cross section, and has more stable mechanical strength. Of course, the insulating support bar may be a strip with a square cross section or other shapes, so long as the insulating support bar can play a role in supporting and isolating.

The inner ring layer of the low-voltage winding 120 is also provided with an inner lead copper bar, the outer ring layer of the low-voltage winding 120 is also provided with an outer lead copper bar, the free ends of the inner lead copper bar and the outer lead copper bar are provided with connecting holes, and the connecting holes are correspondingly matched with the second through holes on the iron core clamping piece 140 and then are fixedly connected.

As shown in fig. 7 and 8, the high voltage winding 130 includes a winding part 1310, a high voltage coil 1320, and a high voltage insulation layer 1330; the winding part 1310 is circumferentially arranged at the inner side of the high-voltage winding, a wire is wound on the winding part 1310 to form a high-voltage coil 1320, and the high-voltage coil 1320 comprises a plurality of coils which are arranged at intervals along the axial direction of the high-voltage winding 130; the high voltage insulation 1330 wraps the high voltage coil 1320 and the winding portion 1310. The high-voltage winding 130 is only provided with the winding part 1310, and the rigid insulating lining barrel is not arranged, so that the structure of the rigid insulating lining barrel is omitted, the heat conduction effect of the high-voltage winding 130 is better, the interface between the high-voltage insulating layer 1330 and the rigid insulating lining barrel is not present, the surface discharge condition of the rigid insulating lining barrel is not present, the material is saved, and the cost is reduced.

In the present embodiment, the winding portion 1310 includes a plurality of comb-shaped winding plates 1311, and the plurality of winding plates 1311 are disposed at intervals and uniformly distributed in the inner circumferential direction of the high-voltage winding 130, and each winding plate 1311 is disposed along the axial direction of the high-voltage winding 130. The high voltage coil 1320 includes a plurality of coils, and at least one coil is disposed between two adjacent comb teeth on the winding plate 1311. The number of the winding plates 1311 is at least two, that is, two, three, four or more, which is not limited herein. In order to make the winding of the wire firm and save the material as much as possible, the number of winding plates 1311 of the 10kV/1000kVA dry type transformer is set to twelve.

The winding plate 1311 is a rectangular plate, the longer side edge of the winding plate 1311 is arranged along the axial direction of the high-voltage winding 130, a plurality of winding grooves 1312 are further formed in the winding plate 1311, the plurality of winding grooves 1312 are arranged along the radial direction of the high-voltage winding 130 and are distributed at intervals along the axial direction of the high-voltage winding 130, and the winding plate 1311 is in a comb shape, namely a plurality of comb teeth are formed on the winding plate 1311. The height of the comb teeth on the winding plate 1311 along the axial direction of the high-voltage winding 130 is defined as tooth height, the tooth heights of the two ends of the winding plate 1311 and the tooth height of the middle part of the winding plate 1311 are larger than those of other parts, because the field intensity of the end parts of the high-voltage coil 1320 is uneven, the tooth heights of the two ends of the winding plate 1311 are set to be larger than a little, a joint for leading out a split wire is needed in the middle part of the winding plate 1311, the tooth height of the middle part of the winding plate 1311 is set to be larger than a little, the distance between the two corresponding adjacent winding grooves 1312 is larger, and a placing space can be reserved for the joint led out from the middle part of the winding plate 1311. At least one section of coil is arranged between two adjacent comb teeth on the winding plate 1311, so that wires are wound in each winding slot 1312, high-voltage coils 1320 are reasonably distributed and arranged, and the sections of coils are arranged at intervals. Meanwhile, a comb tooth region with a slightly larger tooth height is defined as a high comb tooth region, and a comb tooth region with a slightly smaller tooth height is defined as a low comb tooth region. Then, by the above arrangement, the winding plate 1311 is made to sequentially form a first high comb-tooth region, a first low comb-tooth region, a second high comb-tooth region, a second low comb-tooth region, and a third high comb-tooth region from one end toward the other end in the axial direction of the high voltage winding 130. Further, the tooth heights of the first high comb tooth region, the second high comb tooth region, and the third high comb tooth region are not particularly limited, and may be, for example, the same as each other or may be different from each other. And the first high comb tooth region and the third high comb tooth region can be symmetrically arranged about the second high comb tooth region, and the first low comb tooth region and the second low comb tooth region can also be symmetrically arranged about the second high comb tooth region. Of course, an asymmetric arrangement is also possible, without limitation.

When a plurality of winding plates 1311 are circumferentially and uniformly distributed, two ends of all the winding plates 1311 are flush, the winding grooves 1312 on all the winding plates 1311 are matched in a one-to-one correspondence manner in the circumferential direction of the high-voltage winding 130, each section of coil is circumferentially wound by a lead in a corresponding winding groove 1312 on all the winding plates 1311, and the winding plates are balanced in stress and good in mechanical strength.

In other embodiments, in order to make the setting position of the tap clear, the plurality of winding plates can also be fixed in a non-uniform setting manner, that is, the distance between two adjacent winding plates is not equal, for example, the distance between two adjacent winding plates is greater than the distance between any two other winding plates, at this time, each tap is led out from between the two adjacent winding plates, so that the tooth height of the comb teeth in the middle of the winding plates is not required to be set to be greater, and the setting position of each tap can be also set.

In other embodiments, the winding plate may also be an annular disk disposed circumferentially around the high voltage winding. The plurality of winding plates are arranged at intervals along the axial direction of the high-voltage winding, and the wire is wound in the groove formed by two adjacent winding plates.

The winding plate 1311 is further provided with protrusions 1313, where the protrusions 1313 are located at two ends of the winding plate 1311, and in this embodiment, the protrusions 1313 are located inside the end of the winding plate 1313 and are rectangular plates, and in other embodiments, the protrusions may be located at any position of the end of the winding plate and the shape is not limited, for example, the shape of a cylinder, a prism, or the like may be used.

In this embodiment, the winding board 1311 is made of glass fiber impregnated epoxy resin, a plurality of layers of glass fiber cloth are impregnated with epoxy resin and then stacked to a certain thickness, and a rectangular glass fiber reinforced plastic board is formed by compression molding and curing, and a winding groove 1312 is formed in the glass fiber reinforced plastic board, specifically, the winding groove 1312 is formed by turning, so that the winding board 1311 is formed. When the wire is wound, the winding plate 1311 is fixedly connected to the preparation mold through the boss 1313, the winding plate 1311 is not required to be bonded to the preparation mold by an adhesive, the cost can be saved, the assembly time can be saved, and the production efficiency can be improved.

In this embodiment, the winding plate 1311 is molded by compression molding and curing, and in other embodiments, the comb-shaped winding plate may be molded directly by integral casting and curing, so that the process is simplified, and the material of the winding plate is consistent with the foregoing, and will not be described again.

The winding part 1310 is made of the fiber reinforced composite material, has the characteristics of light weight and high strength, ensures that the winding part 1310 has better mechanical strength, can effectively support the winding of a wire, is not easy to damage, and avoids the wire from being scattered and shifted by injection impact force generated when high-temperature vulcanized silicone rubber is injected outside the winding part 1310; and the fiber reinforced composite material has good heat resistance, so that the winding part 1310 is prevented from being deformed due to the excessively high heat generated by the high-voltage coil 1320 in the operation process of the dry-type transformer 10.

Referring to fig. 7 and 8, taking the a-phase transformer 100 as an example, a wire is wound around the outer peripheral surface of the winding portion 1310 to form a high-voltage coil 1320. Specifically, the wires are wound in the winding slots 1312 of the winding plate 1311, so that the high-voltage coils 1320 are distributed at intervals in the axial direction of the high-voltage winding 130, and the wires form two external connections, namely a first external connection D and a second external connection X, after the winding is completed, respectively, the first external connection D is used for connecting a cable, and the second external connection X is used for connecting other external connections, such as in a three-phase transformer, for interconnection with each phase-change transformer. And, the wire is led out of six taps, respectively tap 2, tap 3, tap 4, tap 5, tap 6 and tap 7, in the middle of the high voltage winding 130 in the axial direction thereof, the six taps forming tap switches, tap 2, tap 4 and tap 6 being defined as a first tap switch and tap 3, tap 5 and tap 7 being defined as a second tap switch for convenience of description.

In an application scenario, as shown in fig. 7, 8 and 9, the wires include a first wire and a second wire, the first wire and the second wire are continuous wires, and the first wire and the second wire are covered with an insulating layer, where the insulating layer may be a polyimide film or a glass fiber film, or the insulating layer may be another insulating material such as polyester paint, or may be a combination of multiple insulating materials, which is not limited herein. In fig. 8, for convenience of description, an upper end of the winding part 1310 is defined as a first end, a lower end of the winding part 1310 is defined as a second end, and a first wire is wound from the first end of the winding part 1310 to a middle part of the winding part 1310 in an axial direction of the high voltage winding 130 and three taps are drawn. The first wire is wound from the first end of the winding portion 1310 to the second end of the winding portion 1310, and the first wire is wound in a first winding slot 1312 corresponding to one turn on all the winding plates 1311 to form a first coil 1321, the first coil 1321 is a pancake winding method, only one pancake coil is provided in each winding slot 1312, and at this time, only one pancake coil is provided in each section of coil. The first wire is located at the inner turn wire end of the first end of the winding portion 1310 to form a first external connection D exposed outside the high-voltage insulation layer 1330, that is, the first external connection D is led out at the inner turn wire end of the first section coil 1321 (i.e., the head end of the first wire), the outer turn wire end of the first section coil 1321 extends into a corresponding turn of the second winding slot 1312 on all winding plates 1311 to form a second section coil 1322, and so on until the first wire is wound to the middle of the winding portion 1310, and three taps, that is, tap 6, tap 4 and tap 2 as shown in fig. 7, are led out through the outer turn wire ends of the three sections of coils, respectively, so that the first wire is wound.

The second wire is wound from the middle of the winding portion 1310 to the second end of the winding portion 1310 in the axial direction of the high voltage winding 130, and is led out of the other three taps. Specifically, the second wire starts winding in the next winding slot 1312 adjacent to the tap 2 to form the third segment coil 1323, and continues to wind toward the second end of the winding part 1310 in the same winding manner as the first wire, and three further taps, i.e., tap 3, tap 5 and tap 7, are respectively drawn from the three segments of the coil 1323 until the second wire winds to the corresponding one of the last winding slots 1312 on each of the winding plates 1311 at the second end of the winding part 1310 and forms the terminal segment coil 1324. The outer turn wire end of the second wire at the second end of the winding portion 1310 forms a second external connection X exposed to the outside of the high voltage insulation 1330, i.e., the second external connection X is led out at the outer turn wire end of the terminal section coil 1324 (i.e., the end of the second wire), so that the second wire is wound.

When the wire is wound, the corresponding winding grooves 1312 on all the winding plates 1311 are wound, so that each section of coil formed by winding the wire is perpendicular to the axial direction of the high-voltage winding 130, the winding is convenient, the wire arrangement is neat, and the winding plates 1311 are uniformly stressed and have good mechanical strength.

In this way, the pancake type high-voltage coil 1320 is formed, and the coil structure has better mechanical strength, strong bearing capacity for electromotive force generated by short-circuit current, and better heat dissipation capacity compared with the layered coil with more pancake numbers. In addition, as shown in fig. 7 and 9, in the axial direction of the high-voltage winding 130, the tap 6, the tap 4 and the tap 2 are sequentially distributed to form a first tap changer, the tap 3, the tap 5 and the tap 7 are sequentially distributed to form a second tap changer, the first tap changer and the second tap changer are arranged in parallel, and the six taps form tapping devices of the high-voltage coil 1320, so that the dry-type transformer 10 can regulate voltage according to different operation conditions.

The wire is wound around the winding portion 1310 to form a high-voltage coil 1320, and the high-voltage coil 1320 is annular, the annular width of the high-voltage coil 1320 is defined as the width of the high-voltage coil 1320, and the widths of the high-voltage coil 1320 on each radial section are uniform, that is, the outer side surface of the high-voltage coil 1320 is equidistant from the outer peripheral surface of the high-voltage winding 130, so that the whole high-voltage coil 1320 is in stress balance. Of course, the widths of the coils in the radial cross section may not be exactly the same in consideration of actual operation, and may be substantially the same.

In this embodiment, the second wire is wound from the next winding slot 1312 adjacent to the tap 2 to the last winding slot 1312 at the second end of the winding portion 1310, and in other embodiments, the second wire may be wound from the last winding slot at the second end of the winding portion up to the next winding slot adjacent to the tap 2, except that the second external X is formed first, and then the tap 7, the tap 5, and the tap 3 are sequentially formed. Of course, the winding method of the high-voltage coil 1320 is not limited to the above, and a pancake coil or a layer coil may be formed in other ways as long as the high-voltage winding 130 can be finally formed.

In this embodiment, the tap changer includes six taps, and the dry-type transformer 10 has five gear-stage adjustable voltages at this time, and in other embodiments, the tap changer may also include four taps, that is, the first tap changer and the second tap changer include two taps, respectively, and the dry-type transformer includes three gear-stage adjustable voltages at this time, so long as the actual use requirements of the dry-type transformer are met, and the present invention is not limited thereto.

As shown in fig. 7 and 8, the high voltage winding 130 is formed by wrapping the high voltage coil 1320 and the winding portion 1310 with the high voltage insulating layer 1330. Wherein, the high-voltage insulating layer 1330 is high-temperature vulcanized silicone rubber. Compared with the existing room temperature vulcanization process, the high-temperature vulcanized silicone rubber can enable the high-voltage insulating layer 1330 to be more stable, has higher mechanical property, has better bonding property with the high-voltage coil 1320 and the winding part 1310, and can effectively prolong the service life of the high-voltage insulating layer 1330. In addition, compared with liquid silicone rubber, the silicone rubber filler disclosed by the application is uniformly dispersed, partial discharge caused by filler aggregation is avoided, and the product performance is better. Specifically, the wire is wound on the winding portion 1310 to form a high-voltage coil 1320, the winding portion 1310 and the high-voltage coil 1320 are used as a body to be injected, the body to be injected is placed in a mold of an injection machine, the high-temperature vulcanized silicone rubber is integrally injected on the periphery of the body to be injected by adding the silicone rubber raw material, the high-voltage winding 130 is obtained, the high-temperature vulcanized silicone rubber is adopted for the high-voltage insulating layer 1330, and the insulating performance and the mechanical performance of the high-voltage winding 130 are integrally improved.

After the high-temperature vulcanized silicone rubber is integrally injected in vacuum to cover the high-voltage coil 1320 and the winding part 1310, the high-temperature vulcanized silicone rubber fills the gap between the high-voltage coil 1320 and the winding part 1310 and covers the high-voltage coil 1320 and the winding part 1310, so that the high-voltage winding 130 is integrally in a hollow column shape, and the high-voltage winding 130 can be a hollow cylinder, a hollow elliptic cylinder or other hollow column bodies.

Unlike the prior art, the high-voltage winding 130 of the present application does not include a rigid insulating liner, so that the heat conduction effect of the high-voltage winding 130 is better, and no interface exists between the high-voltage insulating layer 1330 and the rigid insulating liner, so that the surface discharge of the rigid insulating liner is avoided, the material is saved, and the cost is reduced. The dry-type transformer 10 of the present application is low in manufacturing cost and excellent in performance.

An embodiment of the present invention provides a method for manufacturing a high voltage winding 130, comprising the steps of:

step a: the winding part 1310 is disposed and fixed on the preparation mold 20 in the circumferential direction of the preparation mold 20.

As shown in fig. 10, the preparation mold 20 includes a cylinder 21 and two end caps 22 located at two ends of the cylinder 21, and a plurality of clamping holes 23 are provided along the circumferential direction of the end caps 22, and the two end caps 22 are in a symmetrical structure. The cylinder 21 is a hollow cylinder, the end cover 22 is annular, is coaxial with the cylinder 21 and extends outwards along the radial direction at the end part of the cylinder 21, the inner diameter of the end cover 22 is not larger than the inner diameter of the cylinder 21, and the outer diameter of the end cover 22 is larger than the outer diameter of the cylinder 21. The inner diameter of the end cover 22 can be the same as the inner diameter of the cylinder 21, at the moment, the inner wall of the end cover 22 is flush with the inner wall of the cylinder 21, and a connecting rod on the winding machine can freely penetrate through the cylinder 21, so that the assembly of the preparation mold 20 and the winding machine is realized; the inner diameter of the end cover 22 can also be smaller than the inner diameter of the cylinder 21, so long as the connecting rod on the winding machine can freely penetrate through the cylinder 21, and the assembly of the preparation mold 20 and the winding machine can be realized. The cylinder 21 can be a hollow cylinder, a hollow elliptic cylinder or other hollow columnar bodies, the outer surface of the cylinder 21 is matched with the inner surface of the high-voltage winding 130, the hollow cylinder 21 has lighter weight, the preparation mould 20 can be ensured to be in the bearing range of the winding machine, and the hollow cylinder 21 can be used for tool insertion so as to facilitate the connection of the preparation mould 20 and the winding machine. In order to ensure that the injection pressure can be supported by the preparation mold 20 during injection, the cylinder 21 may be made of a hard metal such as iron.

Referring to fig. 11, the end cap 22 is annular and coaxial with the cylinder 21. The annular width of the end cover 22 is larger than the thickness of the cylinder 21, and a plurality of clamping holes 23 can be formed in the end cover 22 to clamp the winding part 1310. Two ends of the winding part 1310 are provided with a plurality of protrusions 1313 which are correspondingly matched with the clamping holes 23, and the winding part 1310 is fixed on the preparation mold 20 through the end cover 22. The clamping hole 23 is located at the position of the end cover 22, which is not connected with the cylinder 21, and in this embodiment, a gap exists between the winding portion 1310 clamped on the clamping hole 23 and the cylinder 21, at this time, the high-voltage insulation layer 1330 can fully cover the winding portion 1310, and a connection interface between the winding portion 1310 and the high-voltage insulation layer 1330 will not appear at the inner surface of the high-voltage winding 130, so that the performance of the high-voltage winding 130 is more stable. And because the wire winding portion 1310 and the cylinder 21 do not need to be adhered and fixed, and the distance is far, the high temperature resistant film does not need to be coated on the outer surface of the cylinder 21, the surface of the cylinder 21 is directly coated with the release agent, and then the wire winding portion 1310 and the cylinder 21 are fixed, so that the method is more rapid and convenient. In other embodiments, the outer surface of the mold may be covered with a high temperature resistant film such as FEP film, and fixed with a high temperature resistant polyimide tape, which may allow easy demolding of the high voltage winding after injection of the high temperature vulcanized silicone rubber. In this embodiment, the clamping hole 23 is a rectangular hole, the protrusion 1313 is a rectangular protrusion, the clamping hole 23 is matched with the protrusion 1313, the rectangular protrusion is more stable than the rectangular hole in the design of the cylindrical protrusion and the circular hole, the winding part 1310 cannot rotate around the circular hole, and further the deflection of the winding part 1310 is avoided. In other embodiments, the shape of the clamping hole follows the shape of the protrusion, and the two shapes need to be matched, so that the clamping hole can accommodate the clamping protrusion.

Further, at least one end cap 22 is fixed to the cylinder 21 in advance. One of the end caps 22 is fixed with the cylinder 21 in advance, for example, by adopting an integral molding or welding mode, when the preparation mold 20 is used, the step of assembling one of the end caps 22 with the cylinder 21 can be omitted, and the other end cap 22 can be connected with the cylinder 21 by means of bolts or clamping after the wire winding part 1310 is clamped, so that the manufacturing process is not affected.

The preparation mold 20 is simple in structure and easy to manufacture, the clamping holes 23 on the end cover 22 can be directly clamped with the winding part 1310, a rigid insulating lining cylinder is not needed for fixing the winding part 1310, the rigid insulating lining cylinder is omitted, the heat conduction effect of the high-voltage winding 130 is better, and an interface between the high-voltage insulating layer 1330 and the rigid insulating lining cylinder does not exist, so that the condition of surface discharge of the rigid insulating lining cylinder is avoided, materials are saved, and the cost is reduced.

Since the high-voltage winding 130 does not include a rigid insulating inner liner, the shape of the inner peripheral surface thereof matches the shape of the outer peripheral surface of the cylinder 21, and by changing the size and shape of the cylinder 21 of the production die 20, it is possible to produce high-voltage windings 130 having different inner diameters and inner peripheral surface shapes.

Specifically, step a includes:

Step a1: one end of the winding portion 1310 is fixed to one end cap 22 of one end of the cylinder 21.

When both end caps 22 and the cylinder 21 are not fixed in advance, one end cap 22 and the cylinder 21 need to be assembled before step a1, and can be connected by bolts or welding.

When the protrusion 1313 at one end of the winding part 1310 is inserted into the clamping hole 23 of the end cover 22, and the winding part 1310 is a plurality of comb-shaped winding plates 1311, the plurality of winding plates 1311 are uniformly distributed and arranged at intervals along the circumference of the preparation mold 20, each winding plate 1311 is arranged along the axial direction of the preparation mold 20, and the protrusion 1313 of the winding plate 1311 is inserted into the clamping hole 23. The number of the engagement holes 23 is equal to or greater than the number of the winding plates 1311. The winding board 1311 is provided with a plurality of winding grooves 1312, so that the winding board 1311 is comb-shaped, and the winding grooves 1312 are used for winding wires subsequently.

Step a2: the other end cap 22 at the other end of the cylinder 21 is fixedly connected to the cylinder 21 after being engaged with the other end of the winding portion 1310.

After the boss 1313 at the other end of the winding part 1310 is inserted into the engagement hole 23 of the end cap 22 at the other end, the end cap 22 at the other end of the cylinder 21 is connected to the cylinder 21 by a bolt.

In other embodiments, the end cap at the other end can be fixedly connected with the cylinder body by a clamping method or the like.

Step b: a high voltage coil 1320 having a tap switch is wound around the wire guide on the winding part 1310. The winding method of the high voltage coil 1320 is as described above, and will not be described here again.

Step c: the winding part 1310 wound with the high-voltage coil 1320 is placed as a body to be injected together with the preparation mold 20 into an injection machine, and high-temperature vulcanized silicone rubber is integrally injected at the periphery of the body to be injected to form a high-voltage insulating layer 1330, thereby obtaining the high-voltage winding 130.

Further, as shown in connection with fig. 7 and 8, the high voltage insulating layer 1330 is high temperature vulcanized silicone rubber. Compared with the existing room temperature vulcanization process, the high-temperature vulcanized silicone rubber can enable the high-voltage insulating layer 1330 to be more stable, has higher mechanical property, has better bonding property with the high-voltage coil 1320 and the winding part 1310, and can effectively prolong the service life of the high-voltage insulating layer 1330. The high voltage insulation 1330 wraps the high voltage coil 1320 and the winding portion 1310 to form the high voltage winding 130. Specifically, the wire is wound on the winding portion 1310 to form a high-voltage coil 1320, the winding portion 1310 and the high-voltage coil 1320 are used as a body to be injected, the body to be injected is placed in a mold of an injection machine, the high-temperature vulcanized silicone rubber is integrally injected on the periphery of the body to be injected by adding the silicone rubber raw material, the high-voltage winding 130 is obtained, the high-temperature vulcanized silicone rubber is adopted for the high-voltage insulating layer 1330, and the insulating performance and the mechanical performance of the high-voltage winding 130 are integrally improved.

After the high-temperature vulcanized silicone rubber is injected in a vacuum manner to cover the high-voltage coil 1320 and the winding part 1310, the high-temperature vulcanized silicone rubber fills the gap between the high-voltage coil 1320 and the winding part 1310 and covers the two ends of the winding part 1310, so that the high-voltage winding 130 is in a hollow column shape as a whole, and the high-voltage winding 130 can be a hollow cylinder, a hollow elliptic cylinder or other hollow column bodies.

Step d: the high voltage winding 130 is released from the production mold 20.

At least one end cap 22 is removed and the high voltage winding 130 is separated from the production tool 20. In this case, if the end cap 22 at one end of the cylinder 21 is fixed in advance by welding or by integral molding, the end cap 22 at the other end can be selectively removed by fixing the end cap 22 by other easy-to-remove means such as bolts, and the specific removal of the end cap 22 at which end is not limited is only required to be able to remove the end cap 22 and separate the high-voltage winding 130 from the preparation mold 20. And only one end cap 22 of the cylinder 21 can be removed, or both end caps 22 of the cylinder 21 can be removed.

Step e: the protrusion 1313 is cut and polished smooth to prevent the generation of partial discharge.

The manufacturing method of the high-voltage winding 130 has simple steps, the required manufacturing mould 20 has simple structure and is easy to manufacture, and the high-voltage winding 130 manufactured by the method omits a rigid insulating lining cylinder, so that the high-voltage winding 130 has better heat conduction effect, and no interface between the high-voltage insulating layer 1330 and the rigid insulating lining cylinder exists, thereby avoiding the surface discharge of the rigid insulating lining cylinder, saving materials and reducing cost.

While the present disclosure and features have been described above with respect to specific embodiments, it will be appreciated that those skilled in the art, upon attaining the teachings of the present disclosure, may readily devise numerous variations and modifications of the above-described structures and materials, including combinations of features that are individually disclosed or claimed herein, and obviously other combinations of such features. Such variations and/or combinations fall within the technical field to which the application relates and fall within the scope of the claims of the application.

Claims

1. A method for manufacturing a high-voltage winding, the high-voltage winding including a winding portion including a plurality of comb-shaped winding plates, a high-voltage coil formed by winding a wire on the winding portion, and a high-voltage insulating layer wrapping the high-voltage coil and the winding portion, the method comprising the steps of:

step a: arranging and fixing a plurality of winding plates on a preparation mold along the circumferential direction of the preparation mold;

Step b: winding the wire on the winding part to form the high-voltage coil with a tap switch;

Step c: placing the winding part wound with the high-voltage coil as a body to be injected together with the preparation mould into an injection machine, and integrally injecting high-temperature vulcanized silicone rubber outside the body to be injected to form the high-voltage insulating layer, so as to obtain the high-voltage winding;

step d: and demolding the high-voltage winding from the preparation mold.

2. The method of manufacturing a high-voltage winding according to claim 1, wherein the manufacturing mold comprises a cylinder and two end caps positioned at both ends of the cylinder, a plurality of clamping holes are provided along a circumferential direction of the end caps, the two end caps are of a symmetrical structure, a plurality of protrusions are provided at both ends of the winding portion, and in the step a, the protrusions are correspondingly matched with the clamping holes and the winding portion is fixed on the manufacturing mold through the end caps.

3. The method of manufacturing a high voltage winding according to claim 2, wherein at least one of said end caps is pre-fixed to said cylinder prior to said step a.

4. A method of manufacturing a high voltage winding according to claim 3, wherein at most one of the end caps is integrally formed with the cylinder or is secured by welding.

5. The method of manufacturing a high voltage winding according to claim 2, wherein said step a comprises:

Step a1: fixing one end of the winding part on one end cover of one end of the cylinder;

step a2: and the other end cover at the other end of the cylinder body is fixedly connected with the cylinder body after being clamped with the other end of the winding part.

6. The method of manufacturing a high-voltage winding according to claim 1, wherein the wire includes a first wire and a second wire, and in the step b, the first wire is wound from a first end of the winding portion to a middle portion of the winding portion in an axial direction of the high-voltage winding and led out of a first tap changer; the second lead is wound from the middle of the winding part to the second end of the winding part along the axial direction of the high-voltage winding, and is led out of the second shunt switch.

7. The method of manufacturing a high voltage winding according to claim 2, wherein in said step d, at least one of said end caps is removed, and said high voltage winding is separated from said manufacturing mold.

8. The method of manufacturing a high-voltage winding according to claim 1, wherein in the step a, the winding portion is disposed and fixed to the manufacturing die in a circumferential direction of the manufacturing die after the mold release agent is coated on an outer surface of the manufacturing die.

9. The method of manufacturing a high voltage winding according to claim 2, further comprising step e) after said step d: cutting the bulges and polishing the bulges to be smooth.

10. The method of manufacturing a high-voltage winding according to claim 2, wherein the snap-fit hole is a rectangular hole, and the protrusion is a rectangular protrusion.